SANTIAGO, Chile, May 11, 2011 (ENS) - A complex multi-dam hydroelectric scheme that conservationists fear will destroy the character of one of Chile's most important wild regions was approved Monday by the Aysén Environmental Review Commission.

The 2,750 megawatt HidroAysén project would include five dams in Patagonia - three on the Pascua River, and two on the Baker River, Chile's largest river by volume of water.

The dams would flood at least 5,700 hectares (22 square miles) of globally rare forest ecosystems, river valleys and farmlands in the Aysén region of southern Chile, including part of Laguna San Rafael National Park.

Dam proponents contend that the country needs the hydropower to keep its economy growing, particularly in view of a reduction in natural gas being imported from neighboring Argentina.

But the project has been the target of Chilean and international campaigners who for five years have been fighting to keep Patagonia's rivers free of dams.

Critics say the HidroAysén approval process has been marred by a flawed Environmental Impact Assessment and conflicts of interest on the part of some members of the commission, which was appointed by Chile's pro-dam President, Sebastian Piñera.

Patricio Rodrigo, executive secretary of the Counsel in Defense of Patagonia, says that Chileans oppposed to the dams will not give up despite the commission's vote.

"We are outraged that the regional environmental review commission has approved this destructive and illegal project against the will of the majority of Chileans," said Rodrigo. "We are calling on President Piñera to overturn this decision and protect Patagonia."

Chile's President Sebastian Pinera took office in March 2011. (Photo courtesy Office of the President)

On Friday, conflict of interest charges were filed against members of the Environmental Review Commission, including regional Governor Pilar Cuevas and other representatives. The charges were accepted on Monday, but an injunction on the commission's vote was not granted.

Several commission members had already recused themselves from the vote due to conflicts of interest, including the regional housing representative, regional environmental representative, regional energy minister, and the mining representative.

Countrywide protests took place Monday and on April 26 that brought thousands of people out into the streets of 17 cities.

A public opinion poll conducted by the global market research company IPSOS in April found that over 61 percent of Chileans are against the project.

"An IPSOS poll found that 61.1 percent of Chileans are against HidroAysén and damming Patagonia, nearly double the figure of only two years ago, said Patricio Segura of the Patagonia Sin Represas (Patagonia Without Dams) coalition.

"We are calling on the Piñera government to respect the will of the people and refuse to approve HidroAysén. Today's actions are just the first in a series of actions aimed at stepping up the pressure on Piñera in the coming weeks," said Segura.

Conservationists say that the campaign for a Patagonia Without Dams is gaining momentum, despite "a multimillion dollar scare tactic campaign" by HidroAysén this year.

Scheduled for completion by 2026, the project is being developed by Enel of Italy and is a joint venture between Chile's largest electrical utility, Endesa, and a smaller utility, Colbún.

The dams are expected to cost roughly US$3.2 billion and the total cost of the scheme, including transmission lines, is estimated at $7 billion. Financing is expected to come mainly from private investment banks in Chile, the United States and Europe.

Anti-dam advocates say that whether or not President Piñera overturns the HidroAysén dams approval, the fight to stop the project is far from over.

The next phase is the Environmental Impact Assessment for the 2,300 kilometer (1,430 mile) long transmission lines needed to export the electricity from Patagonia to Santiago, Chile's capital.

The Environmental Impact Assessment process for the power lines could be even more difficult than the dam assessment, as the lines would affect thousands of Chileans.

Construction of the power lines would require the world's longest clearcut through virgin rainforest, protected areas, national parks, and a geologically risky region full of active volcanoes and prone to earthquakes.

"The HidroAysén dams are a risky investment for Chile and would threaten a region of global significance," said Berklee Lowrey-Evans, Latin America Program associate at International Rivers, a California-based advocacy group.

"Numerous studies have shown that Chile can sustainably and safely meet its energy needs through increased investments in non-conventional renewable energy and energy efficiency," said Lowrey-Evans, "with less environmental, social and economic costs than HidroAysén."